S&P 500 vs. Nasdaq 100 — What's the Difference?
When people say 'I invest in a U.S. index,' the S&P 500 and the Nasdaq 100 often come up as candidates. Both are large U.S. stocks — is it just a difference in name, or a difference in character itself?
They differ from the number of stocks they hold
The S&P 500 holds 500 large U.S. companies (actually 503 stocks, due to overlapping share classes). It covers about 80% of U.S. market cap, so you can regard it as representing 'the whole U.S. market.'
The Nasdaq 100 holds only the 100 largest 'non-financial' companies listed on the Nasdaq. As the name says, it's 100 stocks.
Interestingly, about 85% of the Nasdaq 100's stocks are also included in the S&P 500. In other words, the Nasdaq 100 is close to a subset that extracts the 'large tech and growth stocks' from within the S&P 500.
The key difference: excluding financials and concentrating on tech
The most decisive differences are two.
First, by its rules the Nasdaq 100 holds no financial-sector companies at all. Banks and insurers are excluded. By contrast, the S&P 500 holds all sectors, including financials.
Second, sector concentration differs. According to data, the Nasdaq 100 is so tilted toward tech and growth stocks that four sectors — IT, communications, consumer discretionary, and health care — account for about 85%. Those same four sectors are at about 62% in the S&P 500.
Put simply, understand the Nasdaq 100 as 'tech- and growth-concentrated' and the S&P 500 as 'evenly spread across all sectors.'
Sector weights vary over time. In periods when large tech stocks rose sharply, both indexes' tech weightings grew larger. Treat the numbers here as rough tendencies.
Different character means different drawdown
The Nasdaq 100, concentrated in tech and growth stocks, tends to rise more sharply in upturns, but it also tends to fall more sharply in downturns. The concentration means greater volatility.
A classic example: when the dot-com bubble burst in 2000, the tech-centered index collapsed by a very large amount from its peak (roughly down to the -70% range from the peak), and recovery took a long time. By contrast, the S&P 500, with sectors evenly mixed, had a relatively shallower drawdown over the same period.
That's the key lesson. 'Can rise more' is paired with 'can fall more.' You can't say which index is better; you have to understand each one's volatility and maximum drawdown and weigh for yourself whether it fits your own investment horizon and profile.
よくある質問
Q. Since the Nasdaq 100 rises more, isn't it simply advantageous?
It looks that way if you only look at upturns, but in downturns it can fall more deeply and take longer to recover. There's a history of tech-concentrated indexes collapsing sharply, as in the dot-com bubble. Remember that 'the potential for larger gains' comes as a set with 'the potential for larger losses.'
Q. So which of the two should I choose?
This article doesn't recommend a particular index. After understanding each one's character (concentration vs. diversification, level of volatility, maximum drawdown), it's right to judge for yourself whether it fits your own investment horizon and the range of loss you can bear.
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